Chlorine dioxide has been found to act as a disinfecting agent. It may have application in disinfecting or sterilizing solutions and devices to which they are applied. This technology has been found to be particularly useful when applied to contact lens solutions and contact lenses.
Contact lenses should be periodically disinfected to protect the wearer's eyes from infection and to improve the wearer's comfort. It is often desirable that lens disinfecting be accomplished quickly, e.g., for the convenience of the wearer. However conventional fast-acting disinfectants that are used with contact lenses have a high potential to cause eye irritation. Fast-acting disinfectants, such as hydrogen peroxide, cause a significant ocular irritation if placed directly in the eye. Thus, when using such disinfectants, a thorough rinsing and/or neutralization step is required to remove substantially all traces of the disinfectant. Also, such disinfectants are often not stable and tend to lose their potency over time. A fast-acting, stable lens disinfecting system which is not as prone to cause eye irritation would clearly be advantageous.
In addition to disinfecting contact lenses, they should also be cleaned of protein-based debris periodically. Such lens cleaning is done using proteolytic enzymes. See for example, Karageozian U.S. Pat. No. 3,910,296.
New compositions and methods for disinfecting devices, particularly contact lenses, have been discovered. These compositions and methods utilize the controlled formation of chlorine dioxide from a precursor by a transition metal, thought to be a catalytic process. The ability to control the formation of chlorine dioxide allows one to effectively and efficiently ship and store the chlorine dioxide as an inactive precursor prior to use. Then, substantially on demand, the precursor is activated or promoted to form or provide a disinfecting amount of chlorine dioxide.
An additional benefit of being able to control the formation or release of the chlorine dioxide is that it allows one to sequentially clean the lens using an enzymatic cleaner and then disinfect the lens in a one step process. This is very convenient for the ultimate user, especially a contact lens wearer, and provides the wearer with an easy and time effective way to maintain his or her lenses. The contact lens wearer experiences more comfort and less irritation because his/her contact lenses are more apt to be clean and disinfected.